Stellar Train: I Open a Small Shop on the Train - Chapter 1

The formless ancient world was infested with despicable demons. They hunted and feasted on mankind, keeping the human civilization constantly in a weak and suppressed state.

During the first known year, a magical mountain descended into the world from the realm of the Gods. Carved on this enormous mountain was a message: ‘Heaven Prevails’…

After the Grand Descent, a name that was given to the descending of the mountain, the Three Great Sages made their ways to Mystic Mountain where they learned to harvest what we now call magic, establishing the Mystic Cults and eighty-one sacred shrines to help aid mankind with the cult’s mystic powers against the eternal fight to the death with demons.

- Description from Novelupdates

Aomori, who has a monster-fighting system, came to the world of One-Punch Man and gained the ability to enter various instances.

Therefore, “Founder of the Hero Association”, “NO. “And other titles fell on him one after another.

Comprehensive flow, the main world One Punch Man.

Completed dungeons so far: Pokémon – Demon Slayer – Sword – Pokémon – Digimon – Spell Return – Yokai Comprehensive World (Girls that Noragami Inuyasha can see, etc.) – Pokémon – One Piece-re0-Dragon Ball wait.

- Description from novelbuddy

This is a world shrouded in darkness.The spreading Black Fog corrodes every living creature.The only protection for humanity lies in fire.But as the dark Epoch approached, the fires slowly extinguished.Countless strong Kingdoms became dens for Dark Monsters, humans lost contact with each other, and survivors trembled in the faint solitary light.Until Rod came to this world.“Damn, what's this cow and horse stuff, is it edible?”“This Soul, it's delicious.”“As long as the will of fire remains unextinguished, I believe, one day, humanity will once again illuminate this world and burn all spectral vermin to ashes.”“Even if I'm mired in darkness, bearing the Dream Realm, I can still support this world!”“We've won!”——The world is about to fall, the Abyss looms at our side.And I will raise this Unique flame to light up the world.Yes, I am the last King of Darkness.But...Hello? Anyone, save me.

Hou Niao, devoted to seeking the Dao, found himself mistakenly sent as an undercover agent to the Demon Sword Sect, eagerly anticipating the day he’d be rewarded for his service and could return to the Daoist Sect… Only when he had become a towering figure in the Sword Dao did he sorrowfully realize that there was no one left with the power to recall him!